The shell concept is applied to the midsole and upper mold, providing cushioning and a supportive foothold. The design features a slip-on construction, glossy underlays, and the OTTO 958 'O' moniker on the tongue. The tooling system incorporates FLYTEFOAM™ PROPEL cushioning for comfort and an energized feel. FLYTEFOAM PROPEL™ cushioning shell-inspired upper mold slip-on construction
